Bioinspired helical fiber/elastomer composites with high strength

For general composites, fiber can improve the strength of rubber matrix, but it will damage the original high deformation that affect the toughness. Therefore, to solve this problem, we propose a strategy of constructing rubber-helical fiber composite, which can not only improve the strength of rubber, but also maintain the original high deformation of rubber. Inspired by helical structure in nature, we convert straight fibers into helical fibers by winding. The helical fibers with spring characteristic have high strength and large deformation matching with rubber. The tensile strength and fracture toughness of the composite are 3.51 and 3.41 times those of the rubber matrix, respectively. When the aramid fiber was used instead of nylon fiber, the strength of the composite is 12.81 MPa, which is 17.8 times that of pure rubber matrix, and the mass fraction of the fiber is only about 1.60 %. Furthermore, by analyzing the reinforcement and toughening effect of helical fiber, we have determined that helical fiber plays the role of bearing stress and dispersing stress into three-dimensional space in composites.